JP2006093807A - Image forming method, image forming apparatus and program for use therein - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form an image of exact gray level according to image data on a transmission display screen. <P>SOLUTION: When the gray level for any given color of inputted image data cannot be reproduced by a basic characteristics table prepared previously, a signal processing section 13 generates a basic image formation signal for that color, by subtracting a predetermined signal level from a signal value obtained from the basic characteristics table by conversion, and delivers an image formation signal for correction generated by using a correction characteristics table made previously to a printer 19. The printer 19 forms a basic image color material layer on the screen by the basic image formation signal and arranges a correction image color material layer being formed by the image formation signal for correction at a position substantially different from that of the basic image color material layer at image display. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming method for forming an image on a screen, an image forming apparatus, and a program used therefor.

Conventionally, when various digital printers need to faithfully reproduce color information and output accurate colors, multiple input values are given to the printer, the colors are output, and the output colors are measured. By creating colors, a look-up table showing the relationship between input values and output values is created, and color conversion from input signals to output signals is performed using this look-up table. Output was done.
As a method of generating output image data of a digital printer using a three-dimensional lookup table, for example, there is a data processing method described in the prior document 1. In the above technique, the dynamic range is expanded by combining a plurality of three-dimensional lookup tables representing the relationship between input data and output data.

JP 2003-87585 A

By the way, in a system in which a color material is placed on a transparent support such as a transparent sheet and a transmission image is observed by illuminating with a backlight from the back, there is often a problem that the dynamic range is insufficient.
Here, in order to obtain a high dynamic range in a transmission image, it is necessary to place a very high density color material on the transmission support. For example, in an ink jet printer, the amount of ink that can be absorbed by the transmission support is limited. Therefore, it has been difficult to obtain a high dynamic range.
That is, when an image is formed based on image data exceeding the maximum density on the image forming apparatus side, it is not possible to obtain a density exceeding the maximum density even if an image signal sent to the image forming apparatus is adjusted.
That is, for example, in the case where an image of an autumnal leaves scene is transmissively displayed on a screen that is a translucent support, the maximum density value is set because the thickness of an image forming layer such as an inkjet method or an electrophotographic method is limited. It may be insufficient.

  The present invention has been made in view of the above circumstances, and provides an image forming method, an image forming apparatus, and a program used therefor that are capable of forming an image with an appropriate density according to image data on a screen for transmissive display. The purpose is to do.

  In order to achieve the above object, an image forming method of the present invention is an image forming method in which a color material layer is formed on a screen for transmissive display using a translucent material as a base, based on the image data. When the color density exceeds the maximum density of the color material layer formed on the screen, a plurality of color material layers to be formed on the screen are provided.

  Thereby, even when an image having a color density exceeding the maximum density of the color material layer formed on the screen is formed, an image having an accurate density according to the image data can be formed.

  In the image forming method of the present invention, an image forming signal corresponding to output image data is input to an image forming unit that forms a color material layer on a transmissive display screen having a translucent material as a base. An image forming method for forming the color material layer on the screen based on the image data, wherein a color pattern including a primary color, a secondary color, and a tertiary color is formed on the screen in advance by the image forming unit. The color pattern thus formed is spectrally colored to create a basic characteristic table representing the relationship with the chromaticity value for the image forming signal, and a maximum of seven representatives of the primary, secondary, and tertiary colors of the color pattern From the spectral side color result for the color, a representative color characteristic table representing the relationship between each representative color and the chromaticity value for the image forming signal is created. By multiplying, a maximum of seven characteristic table for correction for each representative color is created, so that a three-dimensional lookup table composed of a total of eight characteristic tables is created. When the color density for one of the pixels cannot be reproduced by the basic characteristic table, a predetermined signal level is subtracted from the signal value obtained by conversion using the basic characteristic table for the color corresponding to the hue that cannot be reproduced. A basic image forming signal is generated to form a basic image color material layer in an amount corresponding to the basic image forming signal, and a correction image forming signal corresponding to the predetermined signal level is stored in the correction characteristic table. The corrected image color material layer generated according to the corrected image formation signal is disposed at a position substantially overlapping with the basic image color material layer at the time of image display. The features.

  As described above, when there is a color density that cannot be reproduced in the basic characteristic table, a correction image signal is generated using the correction characteristic table, and a predetermined signal level is obtained from the signal value obtained by conversion using the basic characteristic table. Since the corrected image color material layer is formed in accordance with the correction image formation signal at a position overlapping the basic image color material layer formed in accordance with the subtracted basic image formation signal, an image having the required color density is reliably formed. be able to.

Further, it is preferable that the color pattern includes a color chart including a plurality of color patches in which output values of specific colors are changed and combined.
Thus, a highly accurate table can be created by using a color chart made of color patches as a color pattern.

Further, it is preferable that a color that cannot be reproduced with the basic characteristic table is predicted from the image data, and only the correction characteristic table corresponding to the predicted color is created.
In this way, by creating a correction characteristic table by predicting unreproducible colors, the number of correction characteristic tables created in advance can be reduced, and the time and effort required to create the correction characteristic table can be reduced. Can be reduced.

In addition, it is preferable to search and set a color that cannot be reproduced by the basic characteristic table in the image data in a preset color order.
In this way, by searching for the possibility of color reproduction in the preset color order, it is possible to reliably check each color.

  The image forming apparatus of the present invention inputs an image forming signal generated in accordance with output image data to an image forming unit that forms a color material layer on a transmissive display screen having a translucent material as a base. An image forming apparatus for forming an image according to the image data on the screen, a basic characteristic table representing a relationship between the image forming signal by the image forming unit and an image chromaticity value, and a representative primary A maximum of eight representative color characteristic tables representing the relationship between a maximum of eight representative colors of color, secondary color, tertiary color, and white and an image forming signal for forming the representative color, and the basic characteristic table A correction characteristic table multiplied by the representative color characteristic table, and a signal processing unit that generates the image forming signal using these tables, and the signal processing unit That is, when the density value for any color cannot be reproduced by the basic characteristic table, for the color that cannot be reproduced, a basic value obtained by subtracting a predetermined signal level from the signal value obtained by conversion using the basic characteristic table. An image forming signal is generated, a correction image forming signal is generated using the correction characteristic table, and the image forming unit forms a basic image color material layer on the screen by the basic image forming signal. The correction image color material layer formed by the correction image formation signal is disposed at a position substantially overlapping with the basic image color material layer when an image is displayed.

  As described above, when there is a color density that cannot be reproduced in the basic characteristic table, the signal processing unit generates a correction image signal using the correction characteristic table, and converts the signal value obtained by conversion using the basic characteristic table. A basic image color material layer and a corrected image color material layer are formed on the screen so as to overlap the basic image color material layer by outputting to the image forming means together with a basic image formation signal obtained by subtracting a predetermined signal level. Thus, an image having a color density can be reliably formed on the screen.

Further, the screen is composed of a plurality of transparent sheets, and the image forming unit forms the basic image color material layer on any of the transparent sheets, and the correction image color material layer is the basic image color material. It is preferable to form on a transparent sheet different from the transparent sheet on which the layer is formed.
As a result, a transparent sheet on which the basic image color material layer is formed by the image forming means and a transparent sheet on which the correction image color material layer is formed are created, and these are superimposed to ensure an image with the required color density. Can get to.

Further, it is preferable that the image forming unit forms the basic image color material layer on one surface of the screen and forms the corrected image color material layer on at least the other surface of the screen.
In this way, by forming the basic image color material layer on one surface of the screen and forming the corrected image color material layer on at least the other surface, an image having a required color density can be obtained with certainty.

Preferably, the screen is composed of a plurality of transparent sheets, and the basic image color material layer and the corrected image color material layer are formed on at least one side of the front and back surfaces of the transparent sheet.
In this way, an image having a required color density is reliably obtained by superimposing a transparent sheet having a basic image color material layer formed on at least one surface and a transparent sheet having a correction image color material layer formed thereon. be able to.

Further, the image processing apparatus includes a non-reproducible color predicting unit that predicts a color whose chromaticity value cannot be reproduced by the basic characteristic table in the image data, and the signal processing unit corresponds to the color predicted by the non-reproducible color predicting unit. It is preferable to create only the correction characteristic table.
In this way, by creating a correction characteristic table by predicting a color that cannot be reproduced by the non-reproducible color prediction means, the number of correction characteristic tables created in advance can be reduced. It is possible to reduce the time and effort required to create the file.

Further, it is preferable that the non-reproducible color predicting means searches for and sets a color whose chromaticity value cannot be reproduced by the basic characteristic table in a preset color order.
As described above, the non-reproducible color predicting means searches for each color with certainty by searching for color reproducibility in a preset color order.

  The program of the present invention generates an image forming signal corresponding to input image data to an image forming means for forming a color material layer on a screen for transmissive display using a translucent material as a base. A program for forming an image, wherein a computer obtains a basic characteristic table representing a relationship between the image forming signal by the image forming means and an image chromaticity value, and representative primary colors, secondary colors, Obtaining a maximum of eight representative color characteristic tables representing the relationship between the representative colors of tertiary colors and white and a maximum of eight representative colors and image forming signals for forming the representative colors; and the basic characteristic table as the representative color characteristic table. A correction characteristic table multiplied by the step, a step of generating the image forming signal using these tables, and a step of generating the input image data That is, when the density value for any color cannot be reproduced by the basic characteristic table, for the color that cannot be reproduced, a basic value obtained by subtracting a predetermined signal level from the signal value obtained by conversion using the basic characteristic table. Generating an image formation signal, generating a correction image formation signal using the correction characteristic table, forming a basic image color material layer on the screen based on the basic image formation signal, and correcting the image; And a step of arranging a corrected image color material layer formed by the formation signal at a position substantially overlapping with the basic image color material layer at the time of image display.

  In this way, when there is a color density that cannot be reproduced in the basic characteristic table, the generation of the correction image signal using the correction characteristic table is executed, and a predetermined signal is obtained from the signal value obtained by conversion using the basic characteristic table. Since the correction image color material layer corresponding to the correction image formation signal is formed at a position overlapping the basic image color material layer formed according to the basic image formation signal obtained by subtracting the level, an image having the required color density Can be reliably formed.

According to the image forming method, the image forming apparatus, and the program used therefor according to the present invention, when there is a color density that cannot be reproduced in the basic characteristic table, a correction image signal is generated using the correction characteristic table, and the basic characteristic table A corrected image color material layer is formed in accordance with the correction image formation signal at a position overlapping the basic image color material layer formed in accordance with the basic image formation signal obtained by subtracting a predetermined signal level from the signal value obtained by conversion by Therefore, an image having a required color density can be reliably formed.
Thereby, even when an image having a color density exceeding the maximum density of the color material layer formed on the screen is formed, an image having an accurate density according to the image data can be formed.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of an image forming method, an image forming apparatus, and a program used therefor according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is a perspective view showing a screen on which an image is formed by the image forming method of the present embodiment, FIG. 2 is a plan view of each screen on which an image is formed, and FIG. 3 is an image forming apparatus of the present embodiment. It is a block diagram which shows a structure.

As shown in FIGS. 1 and 2, the image 1 is obtained by forming a color material layer 5 on each of a plurality of transmissive display screens 3. The screen 3 is formed by forming a translucent material such as a resin into a film shape. A color material layer 5 is formed on the surface of the screen 3 based on image data by an image forming unit including a printer 19 described later. Yes.
And in the state which accumulated these screens 3, a transmission image is observed on the surface side by irradiating light with the illumination 7 from the back side.

Next, an image creating method and an image creating apparatus for creating the image 1 by forming the color material layer 5 on the screen 3 as described above will be described.
As shown in FIG. 3, the image forming apparatus 11 includes a signal processing unit 13 including a computer that performs signal processing on an image signal based on an image creation program. The signal processing unit 13 converts image data into image data. The image signal of the image data from the stored image memory 15 is processed. Then, the signal processing unit 13 outputs the processed image signal to the printer driver 17 as an image forming signal, and causes the printer 19 to print the image on the screen 3.

A table storage unit 21 is connected to the signal processing unit 13, and a three-dimensional lookup table (hereinafter referred to as a 3DLUT) stored in the table storage unit 21 is extracted, and the extracted 3DLUT is used in accordance with a program. The image signal is processed and output as an image formation signal.
A computing unit 23 is connected to the 3DLUT stored in the table storage unit 21, and the computing unit 23 computes the 3DLUT and transmits it to the table storage unit 21.

A spectroscopic measuring device 25 is connected to the calculating unit 23, and the calculating unit 23 calculates a 3DLUT based on the spectral transmittance measurement data transmitted from the spectroscopic measuring device 25.
The spectrophotometer 25 measures the spectral transmittance corresponding to each patch of the color patch image that is the color pattern printed on the color chart 27 printed by the printer 19.

Next, a procedure for creating a 3DLUT in the image forming apparatus 11 will be described.
FIG. 4 is a flowchart illustrating a procedure for creating a 3DLUT used in the image forming method.
First, a color chart 27 is created by printing a color patch image on an OHP sheet by the printer 19 (step 1; hereinafter, abbreviated as S1). Here, the image of the color chart 27 is a patch of 729 colors obtained by dividing each color signal of red (R), green (G), and blue (B) into 9 stages.

  Next, the spectral transmittance Ti (λ) of 729 colors corresponding to each patch of the output image printed on the created color chart 27 is measured by the spectrometer 25 and the measurement data is transmitted to the calculation unit 23 ( S2).

The computing unit 23 sets the spectral transmittance corresponding to the specific color from the spectral transmittance Ti (λ) (i = 1 to 729) of each patch, which is the transmitted measurement data (S3). Here, the specific colors are a primary color composed of yellow (Y), magenta (M), and cyan (C), a secondary color composed of blue (B), green (G), and red (R), and black (Bk). Further, white (W) is included in the tertiary color consisting of Y (255,255,0), M (255,0,255), C (0,255,255), B ( 0, 0, 255), G (0, 255, 255), R (255, 0, 0), Bk (0, 0, 0), W (255, 255, 255).
That is, from the spectral transmittance Ti (λ) of each patch, the representative color characteristic tables Y ₀ (λ), M ₀ (λ), C ₀ (λ), B ₀ (λ), which are made of the spectral transmittance of a specific color, G ₀ (λ), R ₀ (λ), Bk ₀ (λ), and W ₀ (λ) are extracted.

Next, the calculation unit 23 represents the representative color characteristic tables Y ₀ (λ), M ₀ (λ) of the specific colors (eight colors) obtained by extracting the spectral transmittance Ti (λ) of 729 colors obtained in step S2 in step S3. ), C ₀ (λ), B ₀ (λ), G ₀ (λ), R ₀ (λ), Bk ₀ (λ), and W ₀ (λ), respectively, and the chromaticity value is calculated from the result. As a result, Y (λ), M (λ), C (λ), B (λ), G (λ), R (R (8), which represent the relationship between the input signal to the printer 19 and the chromaticity value. (λ), Bk (λ), and W (λ) are created (S4).

  The 3DLUT created by the calculation unit 23 is transmitted to the table storage unit 21 and stored in the table storage unit 21 (S5). It should be noted that Y of Y (λ), M (λ), C (λ), B (λ), G (λ), R (λ), Bk (λ), and W (λ) constituting this 3DLUT (Λ), M (λ), C (λ), B (λ), G (λ), R (λ), and Bk (λ) are the correction characteristic tables, and W (λ) is the basic characteristic table. And stored in the table storage unit 21.

Next, a procedure for forming the image 1 by the image forming apparatus 11 will be described.
FIG. 5 is a flowchart for explaining an image forming procedure on the screen.
First, the signal processing unit 13 performs an image search from the image data from the image memory 15. That is, the 3DLUT including the basic characteristic table W (λ) is first passed through the chromaticity value of the pixel of the image to be printed (S11).

  Then, the signal processing unit 13 determines whether or not the chromaticity value of the pixel of the image to be printed can be reproduced by the printer 19 (S12).

  If there is no non-color reproducible pixel, that is, if the dynamic range of the color density when printed by the printer 19 is sufficient, and if the density does not become insufficient for all pixels, the basic characteristic table of 3DLUT for all pixels W (λ) is applied (S13).

  If there is a pixel whose color cannot be reproduced by the printer 19, that is, the dynamic range of the color density when the printer 19 prints is insufficient, and if there is a pixel whose density is insufficient, One of the 3DLUT correction characteristic tables Y (λ), M (λ), C (λ), B (λ), G (λ), R (λ), and Bk (λ) is set (S14).

  It is determined again whether or not color reproduction is possible for pixels that cannot be reproduced (S15).

  When color reproduction is impossible, other correction characteristic tables Y (λ), M (λ), C (λ), B (λ), G (λ), R (λ), Bk (λ) It is investigated whether color reproduction is possible on the table (S16).

  When color reproduction is possible, a 3DLUT including a correction characteristic table to be applied to the pixel is registered (S17).

  The processes in steps S11 to S17 are repeated until a search is made for color reproducibility for all pixels of the image to be printed (S18).

  An image forming signal is output from the signal processing unit 13 to the printer driver 17, and images are printed on the two screens 3 by the printer 19 (S19). Here, when there is no shortage in the dynamic range of color density and the 3DLUT basic characteristic table W (λ) is applied to all pixels (in the case of step S13), the basic characteristics are displayed on the first screen 3. Printing is performed by outputting a basic image formation signal having a chromaticity value obtained by applying the 3DLUT of the table W (λ) to the printer 19. When printing on the second screen 3, printing is not performed by transmitting a corrected image forming signal based on the chromaticity value of W (255, 255, 255) to the printer 19.

Further, the dynamic range of the color density is insufficient, and the 3DLUT correction characteristic table Y (λ), M (λ), C (λ), B (λ), G (λ), R (λ), Bk (λ ) Is applied (in the case of steps S14 to S17), first, the signal level of the corrected image forming signal generated using the correction characteristic table from the signal value obtained by conversion using the basic characteristic table W (λ) is calculated. Subtraction is performed to obtain a basic image formation signal, and this basic image formation signal is output to the printer 19 to perform printing on the first screen 3.
Next, by generating a corrected image forming signal using the set correction characteristic table and outputting it to the printer 19, the color corresponding to the unreproducible color is printed on the second screen 3 at the maximum density.

  For example, when a desired color can be output using the 3DLUT correction characteristic table G (λ) corresponding to green, the basic characteristic table W (λ) is applied to the first screen 3. Printing is performed by outputting to the printer 19 a basic image forming signal obtained by subtracting the signal level of the corrected image forming signal generated using the correction characteristic table G (λ) from the obtained signal value. Is printed with G (0, 255, 0), which is the maximum density of green, by outputting the corrected image forming signal generated using the correction characteristic table G (λ) to the printer 19.

  As a result, as shown in FIG. 6, an image composed of the basic image color material layer 5a is formed on the first screen 3, and an image composed of the corrected image color material layer 5b having the maximum density is formed on the second screen 3. It is formed.

As described above, according to the image forming method, the image forming apparatus, and the program used therefor according to the present embodiment, when there is a color density that cannot be reproduced by the basic characteristic table W (λ), the correction characteristic table Y (λ) , M (λ), C (λ), B (λ), G (λ), R (λ), and Bk (λ) are used to generate a correction image signal and converted by the basic characteristic table W (λ) The corrected image color material layer 5b is formed according to the correction image formation signal at a position overlapping the basic image color material layer 5a formed according to the basic image formation signal obtained by subtracting a predetermined signal level from the signal value obtained in this manner. Therefore, an image having a required color density can be reliably formed.
Accordingly, even when an image having a color density exceeding the maximum density by the color material layer 5a formed on the screen 3 is formed, an image having an accurate density corresponding to the image data can be formed.

  In the above embodiment, the 3DLUT correction characteristic tables Y (λ), M (λ), C (λ), B (λ), G (λ), and R (λ) for pixels that cannot reproduce colors. , Bk (λ) are examined in order, but a color with insufficient color density dynamic range may be predicted in advance from image data, and a 3DLUT may be created based on this prediction.

  In this way, it is possible to perform a survey with priority over the table for the predicted color, to improve processing efficiency, and for correction except for the basic characteristic table W (λ) in the 3DLUT. The characteristic tables Y (λ), M (λ), C (λ), B (λ), G (λ), R (λ), and Bk (λ) need only be created corresponding to the predicted color. This saves processing time.

In this case, an unreproducible color predicting unit that predicts a color whose chromaticity value cannot be reproduced by the basic characteristic table W (λ) in the image data is provided, and the signal processing unit 13 is predicted by the unreproducible color predicting unit. Only the correction characteristic table corresponding to the color may be created.
Further, the unreproducible color predicting means searches for and sets a color in which the chromaticity value cannot be reproduced by the basic characteristic table W (λ) in a preset color order, and reliably checks each color. Anyway.

In the above embodiment, the basic image color material layer 5a is formed on the first screen 3, and the corrected image color material layer 5b is formed on the second screen 3. However, the corrected image color material layer 5b is Not only the second screen 3 but also the corrected image color material layer 5b may be formed on the back surface of the first screen 3 having the basic image color material layer 5a formed on the surface, as shown in FIG.
In this case, the signal processing unit 13 performs image signal processing considering only the transmittance of one screen 3.

Further, the number of the screens 3 is not limited to the above-described embodiment. For example, as shown in FIG. 8, the corrected image color material layer 5b is formed on one screen 3 on which the basic image color material layer 5a is formed. A plurality of screens 3 may be overlapped.
Here, when the required image density is high, a plurality of correction screens 3 on which the corrected image color material layer 5b of the same color is formed are stacked.

  In FIG. 9, the corrected image color material layer 5 b is formed on the back surface of the first screen 3 having the basic image color material layer 5 a formed on the front surface, and a plurality of sheets are overlapped on the first screen 3. The corrected image color material layer 5 b is formed on the front and back surfaces of the screen 3. Also, as shown in FIG. 10, a correction screen 3 for forming the corrected image color material layer 5b may be provided for each color to be corrected.

It is a perspective view which shows the screen which formed the image by the image forming method of this embodiment. It is a top view of each screen in which an image was formed. 1 is a block diagram illustrating a configuration of an image forming apparatus according to an exemplary embodiment. It is a flowchart explaining the creation procedure of 3DLUT used with an image formation method. It is a flowchart explaining the formation procedure of the image on a screen. It is sectional drawing of two screens in which the color material layer was formed on the surface. It is sectional drawing of the screen of 1 sheet in which the color material layer was formed in the front and back. It is sectional drawing of the screen of several sheets with which the color material layer was formed in the surface. It is sectional drawing of the several screen with which the color material layer was formed in the front and back. It is explanatory drawing explaining the example which overlaps the screen for a correction | amendment for every color to correct | amend.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image 3 Screen 5 Color material layer 5a Basic image color material layer 5b Correction | amendment image color material layer 11 Image forming apparatus 13 Signal processing part 19 Printer (image formation means)
27 Color chart

Claims (12)

An image forming method for forming a color material layer based on image data on a transmissive display screen having a translucent material as a base,
An image forming method comprising: providing a plurality of color material layers to be formed on the screen when a color density of the image data exceeds a maximum density by a color material layer formed on the screen. An image forming signal corresponding to output image data is input to image forming means for forming a color material layer on a transmissive display screen having a translucent material as a base, and the color material layer is applied to the screen. An image forming method for forming based on the image data,
A color pattern including a primary color, a secondary color, and a tertiary color is previously formed on the screen by the image forming unit, and the formed color pattern is spectrally colored to obtain a chromaticity value for the image forming signal. A basic characteristic table representing the relationship is created, and the chromaticity values for the image forming signal for each representative color from the spectral side color results for the maximum seven representative colors of the primary, secondary and tertiary colors of the color pattern. A representative color characteristic table representing the relationship between the representative color characteristic table and the basic characteristic table is multiplied to create a maximum of seven characteristic characteristic correction tables for each representative color. Create a 3D lookup table consisting of characteristic tables,
Of the input image data, when the color density for any pixel cannot be reproduced by the basic characteristic table, the color corresponding to the hue that cannot be reproduced is obtained by conversion using the basic characteristic table. A basic image forming signal obtained by subtracting a predetermined signal level from the signal value is generated to form a basic image color material layer in an amount corresponding to the basic image forming signal, and for correction corresponding to the predetermined signal level An image forming signal is generated using the correction characteristic table, and a corrected image color material layer formed in accordance with the corrected image formation signal is positioned so as to substantially overlap the basic image color material layer when displaying an image. An image forming method comprising disposing the image forming method.   The image forming method according to claim 2, wherein the color pattern includes a color chart including a plurality of color patches obtained by changing output values of specific colors.   The color of the image data that cannot be reproduced by the basic characteristic table is predicted, and only the correction characteristic table corresponding to the predicted color is created. 3. The image forming method according to 3.   5. The image data according to any one of claims 2 to 4, wherein a color whose chromaticity value cannot be reproduced by the basic characteristic table in the image data is searched and set in a preset color order. The image forming method described. An image forming signal generated according to output image data is input to image forming means for forming a color material layer on a transmissive display screen having a translucent material as a base, and the image data is input to the screen. An image forming apparatus for forming an image according to
A basic characteristic table representing the relationship between the image forming signal and the image chromaticity value by the image forming means; representative primary colors, secondary colors, tertiary colors, and white representative colors of up to eight colors; and the representative colors A maximum of eight representative color characteristic tables representing the relationship with the image forming signal for forming the image and a correction characteristic table obtained by multiplying the basic characteristic table by the representative color characteristic table are created. A signal processing unit for generating the image forming signal using
When the density value for any color of the input image data cannot be reproduced by the basic characteristic table, the signal processing unit converts the color that cannot be reproduced by the basic characteristic table. A basic image formation signal obtained by subtracting a predetermined signal level from the obtained signal value is generated, and a correction image formation signal is generated using the correction characteristic table,
The image forming unit forms a basic image color material layer on the screen based on the basic image formation signal, and the correction image color material layer formed by the correction image formation signal is displayed when the basic image color material layer is displayed. An image forming apparatus, wherein the image forming apparatus is disposed at a position substantially overlapping with the image forming apparatus.   The screen is composed of a plurality of transparent sheets, and the image forming unit forms the basic image color material layer on any of the transparent sheets, and the correction image color material layer is formed on the basic image color material layer. The image forming apparatus according to claim 6, wherein the image forming apparatus is formed on a transparent sheet different from the formed transparent sheet.   7. The image forming means forms the basic image color material layer on one surface of the screen, and forms the corrected image color material layer on at least the other surface of the screen. The image forming apparatus described.   9. The screen according to claim 6, wherein the screen is composed of a plurality of transparent sheets, and the basic image color material layer and the correction image color material layer are formed on at least one side of the front and back surfaces of the transparent sheet. The image forming apparatus according to claim 1.   The image data includes non-reproducible color predicting means for predicting colors whose chromaticity values cannot be reproduced by the basic characteristic table, and the signal processing unit corresponds to the color predicted by the non-reproducible color predicting means. The image forming apparatus according to claim 6, wherein only the correction characteristic table is created.   11. The image forming apparatus according to claim 10, wherein the non-reproducible color predicting unit searches for and sets a color whose chromaticity value cannot be reproduced by the basic characteristic table in a preset color order. A program for generating an image forming signal corresponding to input image data and forming an image on the screen for image forming means for forming a color material layer on a screen for transmissive display using a translucent material as a base. Because
By computer
Obtaining a basic characteristic table representing a relationship between the image forming signal by the image forming unit and an image chromaticity value;
Obtaining a maximum of eight representative color characteristic tables representing a relationship between a representative primary color, a secondary color, a tertiary color, and a maximum of eight representative colors of white and an image forming signal for forming the representative color;
Obtaining a correction characteristic table by multiplying the basic characteristic table by the representative color characteristic table;
Generating the image forming signal using these tables;
In the input image data, when the density value for any color cannot be reproduced by the basic characteristic table, the color that cannot be reproduced is determined from the signal value obtained by conversion using the basic characteristic table. Generating a basic image formation signal obtained by subtracting the signal level of the correction image, and generating a correction image formation signal using the correction characteristic table;
A position in which a basic image color material layer is formed on the screen by the basic image formation signal and the correction image color material layer formed by the correction image formation signal substantially overlaps the basic image color material layer when displaying an image. Step to be placed on,
A program characterized by having executed.

Images